190 LYCOPODITES, PTILOPHYTON, PSILOTITES, 



himself inclines to this comparison, though elsewhere ] he conceives of these 

 plants as 'synthetic or generalised plants,' such as Goppert meant by his 

 prototypes, which unite the characters of Lycopodiaceae and Ferns. Now 

 this would be all very right and good, if we could have more clear and exact 

 information about these characters. Dawson's description of the genus 

 rests chiefly on the impression made upon him in his repeated researches at 

 the localities where the fossils are found, especially Gaspe\ Of the correct- 

 ness of this impression in kind and degree we, who are dependent on the 

 few and as a rule ill-preserved specimens in European collections, are the 

 less able to judge, because Dawson unfortunately gives no exact description 

 of individual specimens, though it is this which is so needful, but puts us off 

 with an account of the general idea which he has drawn from his study of 

 them. The botanist cannot possibly feel inspired with any great confidence, 

 when side by side with better specimens of Psilophyton in the collections 

 at London, Strassburg or Gottingen he sees others named by Dawson him- 

 self, which appear to him to be quite undeterminable remains of some kind 

 of leaf-stalk. Dawson 2 has determined as Psilophyton princeps and Ps. 

 robustius numerous remains in the collection at Edinburgh, which according 

 to Peach are common in the Middle Devonian beds of Scotland but have 

 been hitherto generally taken for ' fucoids or roots.' Considering the 

 inclination at the time to determine fossil objects from these older forma- 

 tions, these remains must certainly have been regarded as very formless 

 things. Nor is the comparison with Eophyton, Torell :i (see on p. 46) very 

 reassuring. There is only one of Dawson's species of Psilophyton which 

 supplies real tangible characters, namely Ps. princeps, which is found in 

 many localities in Canada and New Brunswick in the entire series of forma- 

 tions from the Upper Silurian to the Upper Devonian. I have seen several 

 tolerably good specimens of this species, and they agree with Dawson's 

 figures 4 . The erect stems or branches have attached to them at a right 

 angle somewhat numerous thorn-like processes, rudimentary leaves accord- 

 ing to Dawson, and where these are wanting their point of attachment is 

 shown by a small ovoid scar. The upper end when preserved is bent 

 inwards in the shape of a hook or crosier, as in young fern-leaves. The 

 branching is rather copious, sometimes plainly dichotomous with small 

 divergence on the part of the daughter-members, elsewhere on the same 

 specimens apparently monopodial ; we shall not be wrong in assuming that 

 the development of the stem was sympodial. The delicate curved extremi- 

 ties, detached and looking like snail-shells, fill entire beds of slate at Gasp^ 5 . 

 The stems when fully grown show woody structure according to Dawson, 

 and their appendages are thorn-like and rigid. We have descriptions also 



1 Dawson (1), p. 38. 2 Dawson (1), vol. i. p. 77. 3 Dawson (1), vol. ii, p. 79. * Dawson 

 (1), vol. i, t. y. "' Dawson '5 , p. 480. 



